#ifndef __M_FORMAT_H__
#define __M_FORMAT_H__

// 日志信息格式化
#include <iostream>
#include <time.h>
#include <vector>
#include <string>
#include <assert.h>
#include <sstream>

#include "level.hpp"
#include "message.hpp"

namespace log
{
    // 抽象格式化子项基类
    class FormatItem
    {
    public:
        using ptr = std::shared_ptr<FormatItem>;
        virtual void format(std::ostream &out,const LogMessage &msg) = 0;
    };

    // 派生格式化子项子类--消息,等级,时间,文件名,行号,线程id,日志器名,制表符,换行,其他
    class MsgFormatItem : public FormatItem
    {
        void format(std::ostream &out,const LogMessage &msg) override
        {
            out << msg._payload;
        }
    };

    class LevelFormatItem : public FormatItem
    {
        void format(std::ostream &out,const LogMessage &msg) override
        {
            out << LogLevel::toString(msg._level);
        }
    };

    class TimeFormatItem : public FormatItem
    {
    public:
        TimeFormatItem(const std::string &fmt = "%H:%M:%S") : _time_fmt(fmt)
        {
        }
        void format(std::ostream &out,const LogMessage &msg) override
        {
            struct tm t;
            localtime_r(&msg._ctime, &t);
            char tmp[32] = {0};
            strftime(tmp, 31, _time_fmt.c_str(), &t); // 按照特定格式，格式化字符串
            out << tmp;
        }

    private:
        std::string _time_fmt; //%H:%M:%S
    };

    class FileFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out,const LogMessage &msg) override
        {
            out << msg._filename;
        }
    };

    class LineFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out,const LogMessage &msg) override
        {
            out << msg._line;
        }
    };

    class ThreadFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out,const  LogMessage &msg) override
        {
            out << msg._tid;
        }
    };

    class LoggerFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMessage &msg) override
        {
            out << msg._logger;
        }
    };

    class TabFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, const LogMessage &msg) override
        {
            out << "\t";
        }
    };

    class NLineFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out,const LogMessage &msg) override
        {
            out << "\n";
        }
    };
    class OtherFormatItem : public FormatItem
    {
    public:
        OtherFormatItem(const std::string &str) : _str(str)
        {
        }
        void format(std::ostream &out,const LogMessage &msg) override
        {
            out << _str;
        }

    private:
        std::string _str;
    };
    /*
        %d 表示日期，包含子格式{[%H:%M:%S]}
        %t 表示线程ID
        %c 表示日志器名称
        %f 表示源码文件名
        %l 表示源码行号
        %p 表示日志等级
        %T 表示制表符缩进
        %m 表示主体信息
        %n 表示换行
    */
   
    class Formatter
    {
    public:
        using ptr = std::shared_ptr<Formatter>;
        Formatter(const std::string &pattern = "[%d{%H:%M:%S}][%t][%c][%f:%l][%p]%T%m%n") : 
        _pattern(pattern)
        {
            assert(parsePattern());
        }

        // 对msg进行格式化
        void format(std::ostream &out,const LogMessage &msg)
        {
            for (auto &item : _items)
            {
                item->format(out, msg);
            }
        }
        std::string format(const LogMessage &msg)
        {
            std::stringstream ss;
            format(ss, msg);
            return ss.str();
        }

    private:
        // 对格式化规则字符串进行解析
        bool parsePattern()
        {
            // 1.对格式化规则字符串进行解析
            // ab%%cde[%d{%H:%M:%S}][%p]%T%m%n
            //[%d{%H:%M:%S}][%t][%c][%f:%l][%p]%T%m%n
            std::vector<std::pair<std::string, std::string>> fmt_order;
            size_t pos = 0;
            std::string key, val;
            while (pos < _pattern.size())
            {
                // 处理原始字符串--判断是否为%,不是就是原始字符
                if (_pattern[pos] != '%')
                {
                    val.push_back(_pattern[pos++]);
                    continue;
                }

                // 到此位置,表示pos位置是%字符, %%处理称为一个原始%字符
                if (pos + 1 < _pattern.size() && _pattern[pos + 1] == '%')
                {
                    val.push_back('%');
                    pos += 2;
                    continue;
                }

                // 到此表示原始字符串处理完毕
                if (val.empty() == false)
                {
                    fmt_order.push_back(std::make_pair("", val));
                    val.clear();
                }

                // 到此,后面表示是个格式化字符
                pos += 1;
                if (pos == _pattern.size())
                {
                    std::cout << "%之后,没有对应的格式化字符!" << std::endl;
                    return false;
                }
                key = _pattern[pos];
                // pos指向格式化字符后的位置
                pos += 1;
                if (pos < _pattern.size() && _pattern[pos] == '{')
                {
                    pos += 1; // pos指向{之后，子规则起始位置
                    while (pos < _pattern.size() && _pattern[pos] != '}')
                    {
                        val.push_back(_pattern[pos++]);
                    }
                    // 没有遇到}，表示格式错误
                    if (pos == _pattern.size())
                    {
                        std::cout << "子规则{}匹配出错!\n";
                        return false;
                    }
                    pos += 1;
                }
                fmt_order.push_back(std::make_pair(key, val));
                key.clear();
                val.clear();
            }
            for (auto &it : fmt_order)
            {
                _items.push_back(createItem(it.first, it.second));
            }
            return true;
        }
        // 根据不同的格式化字符创建不同的格式化子项对象
        FormatItem::ptr createItem(const std::string &key, const std::string &val)
        {
            if (key == "d")
                return std::make_shared<TimeFormatItem>(val);
            if (key == "t")
                return std::make_shared<ThreadFormatItem>();
            if (key == "c")
                return std::make_shared<LoggerFormatItem>();
            if (key == "f")
                return std::make_shared<FileFormatItem>();
            if (key == "l")
                return std::make_shared<LineFormatItem>();
            if (key == "p")
                return std::make_shared<LevelFormatItem>();
            if (key == "T")
                return std::make_shared<TabFormatItem>();
            if (key == "m")
                return std::make_shared<MsgFormatItem>();
            if (key == "n")
                return std::make_shared<NLineFormatItem>();
            if (key.empty())
                return std::make_shared<OtherFormatItem>(val);
            std::cout << "没有对应的格式化字符:%" << key << std::endl;
            abort();
            return FormatItem::ptr();
        }

    private:
        std::string _pattern; // 格式化规则字符串
        std::vector<FormatItem::ptr> _items;
    };
}
#endif
